Telegraph-key



YR MK m R G PB m AT a d 0 M 0 m No. 437,510. Patented Sept. 30. 1890.

1'"! new. nuns cm, mum-mm, mumm'cm, a c

' UNITED STATES PATENT OFFICE.

ARTHUR F. PURDY, OF LAWRENCE, CALIFORNIA.

, ,TELEG RAPHQKEY.

1 srncrrrcncrxon ma part of Letters Patent No. 437,510,1iatd September so, 1890.

' Application filed April 15, 1890. Serial No. 848,050. (No model.)

' To all whom it may concern.-

Be it known that I, ARTHUR F. PUR-DY, a

citizen of the United States, residing at Lawrence, Santa Clara county, State of California, have invented an Improvement in Telegraph- Keys of which the following a full, clear, and exact description.

My invention relates to telegraph-keys; and it consists in the novel constructions hereinafter fully described, and specifically pointed out in the claims.

The general object of my invention is to provide a simple and effective device of this class. Particular objects and ad vantages will be hereinafter set forth.

Referring to the accompanying drawings for a more complete explanation of my invention, Figure 1 is aperspective view of my key. Fig.

- 2 is a detail showing the conical contacts in section. I

A is the bed-plate or frame of the key, having extending downwardly from it the bolts a, provided with washersand thumb-nuts 0., whereby the key is adapted to be secured to the table.

Bis the lever of the key, having at its outer end the usual button I). This lever is mounted as follows: Rising from the frame A are standards O, in which is journaled the pivot-pin b of the lever. On each edge of these standards is secured in any suitable manner, as by small rivets, pins, screws, or by soldering, a steel plate D, which projects inwardly far enough beyond the inner surface of the stand ards to come up closely to the sides of the lever, and thereby form for it guides, which firmly hold the lever, and, while permitting its free up-and-down movement, avoid and prevent any lateral play. The inner surfaces of the standards do not come up close to the lever, so that there is only a small frictional surface due to the guides. These guides, being of steel, do not wear, but will hold the lever firmly in its position, as described.

In the rear arm of the bed-plate Ais mounted the spring-adjusting screw E, the lower end of which is in contact or connection with the adjustingspring F, the lower end of said spring being properly seated in the extreme rear end or portion of the lever B.

G is the limiting or stop screw of the lever, the lower end of which bears on the bedplate.

and simple. It is narrower than keys generally used, while at the same time it is no longer and no higher. where many keys are used in one office.

The adj usting-spring'F being arranged at the extreme back or rear end of the lever, the full effect is obtained, and it can be adjusted to suit the taste of the sendingoperator. There is no side motionof the main lever, and its pivotal connection is of such a character as to be very desirable and is not liable to get out of order. The strips of steel on either side hold it perfectly rigid and avoid or reduce friction by projecting inwardly beyond the surface of the standards, so that the sides of the key have but small frictional surface to bear against.

It will be noticed that, instead of the usual pins which form the contact-points of ordinary keys, I make my points conical with perfect' apices; give the finest and most perfect contact. The advantage of the perfect contact is in avoiding what is known as sticking. By this is meant the jumping, as it were, of the current frompoint to point when they are open. To fully realize this advantage, the points should have perfect apices, for if they be truncated to even the slightest extent they become no more and have no other effect than the ordinary blunt-ended pins; but Where the apices are perfect the contact between the two points is of the finest nature and effects as good a result, as far as not sticking is concerned, as very fine-pointed pins would, but without the disadvantage of such pins, of rapidly wearing out.

It is common in using the ordinary keys to stop from time to time and set the points farther apart before continuing; but with my key the points may he set so close together that there will scarcely be any perceptible motion, and yet there will be no sticking.

This is of advantage These apices coining, together The main'lever may bemade either heavy or light, as the operator may wish. The lighter ones'are usually preferred; but the heavier ones are sometimes desired.

Having thusdeseribed my invention, what I claim as new, and desire to secure by Let- 1 the bed-plate, the key-lever pivoted thereon,

ters Patent, is

1. In a telegraph-key, the bed-plate having the side standards, in combination with the key-lever pivoted in said standards and the guide-strips on the edges of the standards, their inner surfaces projecting beyond the inner surfaces of said standardsand bearing against the sides of the key-lever, whereby lateral motion is prevented and wear avoided, substantially as herein described.

2. In a telegraph-key, the combination of the adjustin -spring seated in the rear end "of the lever, and the set-screw for regulating said spring, substantially as herein described. '3. In a telegraph-key, opposing contact points, each conically-shaped with perfect apices, one of said points being smaller than the other, substantially as herein described.

' 4. In a telegraph-key, the combination of the bed-plate, the key-lever pivoted in the bed-plate, the conical contact-point on the bed-plate, and the smaller conical contactpoint on the key-lever, both of said contactpoints having perfect apices, substantially as herein described.

5. A telegraph-key consisting of the combination of the bed-plate having the standards, the key-lever pivoted in said standards, the guide bars or strips on the edges of the standards bearing against the sides of the lever, the adj usting-spring at the rear end of the lever, the set-screw for controlling the spring, the switch-leverunder thekey-lever, the contact-spring of said switch-lever, and the conical contactpoints of the bed-plate and key-lever, substantially as herein described.

In witness whereof I have hereunto set my hand.

ARTHUR F. PURDY. Witnesses:

RUSH MCCOMAS, D. W. HERRINGTON. 

